1. Field of the Invention
The present invention generally relates to an air conditioner and, more particularly, to the air conditioner particularly suited for use in an automobile.
2. Description of the Prior Art
An automobile air conditioner of a type installed in the ceiling in the passenger s compartment of an automobile body structure is well known in the art and is disclosed in, for example, the Japanese Laid-open Utility Model Publications No. 63-22213 and No. 63-24011 published in 1988. According to these publications, the prior art automobile air conditioner employs a blower in the form of a centrifugal fan.
Where a centrifugal fan is employed for the blower, the assembly as a whole tends to be relatively bulky with no opportunity available for reducing the thickness thereof as measured from the ceiling down to the bottom of the assembly. As is well known to those skilled in the art, the blower assembly employing a centrifugal fan has a construction wherein air is sucked into the assembly in an axial direction along the shaft about with the fan rotates and is discharged from the circumference of the assembly radially outwardly, i.e., in a centrifugal direction. Therefore, drastic reduction of the diameter of the centrifugal fan is not possible.
In particular, the first mentioned Japanese publication discloses the disposition of the blower assembly with the fan shaft lying horizontal, i.e., generally parallel to the ceiling. The horizontal disposition of the fan shaft causes the fan casing for encasing the centrifugal fan to protrude downwards from the ceiling and into the interior of the automobile body structure through a distance corresponding to the diameter of the centrifugal fan.
Also, the width of the centrifugal fan as measured in a direction parallel to the fan shaft is considered to be an optimum value if it is generally equal to the radius of the centrifugal fan. Accordingly, where the blower assembly is installed with the fan shaft lying vertical, i.e., generally perpendicular to the ceiling, such as disclosed in the second mentioned Japanese publication, the blower assembly not only requires a width somewhat proportional to the diameter of the centrifugal fan, but also the disposition of a fan drive motor so as to be oriented in a direction parallel to the fan shaft. Because of these factors, the thickness of the blower assembly as measured from the ceiling down to the bottom of the blower assembly cannot be drastically reduced.
Considering now the layout of an automobile body structure in general, the height is generally limited from the standpoint of body aerodynamics, body stability, and other factors and/or by law and, therefore, it has long been considered a problem to reduce the bulkiness of the blower assembly in order for it to be installed inside the passenger's compartment.
Also, regardless of the type of the automobile air conditioner particularly suited for installation in the ceiling in the passenger's compartment, the apparatus is required to have a relatively high durability and rigidity in view of the fact that any automobile during running undergoes bumpy motions and tilts and that the apparatus is therefore subjected to severe vibrations.